Martin R. Owen

Kinematic analysis of the gait of 10 labrador retrievers during treadmill locomotion

The trotting gait of 10 sound, adult labrador retrievers was analysed using kinematic gait analysis on a purpose-built treadmill using video-based motion analysis software. The maximal angular displacement, minimal angular displacement, average angular displacement, and the maximal positive and negative angular velocities of the right elbow and right stifle were measured over five gait cycles at defined time points during each of five two-minute sessions. The dogs’ trotting gait was not repeatable, either for individual dogs during the first session or between sessions, or between dogs at the same time points during a session.

Joint angle, moment and power compensations in dogs with fragmented medial coronoid process

Fragmented medial coronoid process (FMCP) is the most common cause of forelimb lameness in juvenile medium and large breed dogs; however methods of assessing the disruption to their gait remain subjective. The purpose of this study was to objectively quantify the mechanical disruptions to gait in dogs with arthroscopically confirmed unilateral FMCP. Seven dogs underwent full inverse dynamic analysis at the time of diagnosis. Kinematic and force data were collected from both forelimbs at trot. Stance phase joint angles, net joint moments and net joint powers were calculated using custom software. There were gross differences in kinetic and kinematic patterns between FMCP affected and compensating forelimbs. Stance time was 0.24 sec on the lame side and 0.26 sec on the compensating side. The shoulder and the elbow were more flexed at ground contact, and elbow, carpal and MCP joints had smaller ranges of motion on the lame side. Net joint moments were significantly reduced (P < 0.05) in the elbow, carpal and MCP joints of the FMCP affected limb. Net joint powers were likewise significantly smaller (P < 0.05). However, the overall moment and power patterns persisted. Total limb support moment was significantly smaller on the affected side (P < 0.05). Total limb power was significantly reduced on the affected side (P < 0.05) being most affected in its propulsive phase in the second half of stance. Inverse dynamic analysis of this clinical condition is an objective means by which to assess the mechanical disruption to gait.

A retrospective study of the MRI findings in 18 dogs with stifle injuries.

OBJECTIVES To make an objective assessment of the usefulness of magnetic resonance imaging in the diagnosis of meniscal damage and cranial cruciate ligament disease in the canine stifle by comparing magnetic resonance imaging findings with surgical findings. METHODS Magnetic resonance images of 18 stifles from 18 dogs which had undergone magnetic resonance imaging for the investigation of stifle disease were reviewed. For every stifle, the menisci and cranial cruciate ligaments were assessed according to predetermined criteria. The magnetic resonance imaging findings were compared with the reported surgical findings and the sensitivity, specificity, positive and negative predictive values (PPV and NPV) were calculated using the surgical findings as the gold standard. Kappa analysis was used as an objective measure of agreement between surgical and magnetic resonance imaging findings. For 11 stifles, meniscal evaluation by three different observers was used to measure interobserver agreement using Kappa analysis. RESULTS Magnetic resonance imaging was demonstrated to be an accurate technique in the detection of meniscal injury (k=0.86), with excellent interobserver agreement (k=0.89 to 1.0). Disruption of cranial cruciate ligament continuity and an increase in ligament intensity were found to be useful criteria in the diagnosis of cranial cruciate ligament rupture. CLINICAL SIGNIFICANCE Magnetic resonance imaging offers a non-invasive alternative to exploratory surgery in the evaluation of cranial cruciate ligament and meniscal disease.

Conservative Versus Arthroscopic Management for Medial Coronoid Process Disease in Dogs: A Prospective Gait Evaluation

OBJECTIVE To investigate, using objective gait analysis, the long-term outcome of dogs with medial coronoid process disease (MCPD) treated with conservative management (CM) versus arthroscopic treatment (AT). STUDY DESIGN Prospective clinical trial. ANIMALS Dogs (n = 20) with unilaterally confirmed MCPD. METHODS Eleven dogs were treated arthroscopically with removal of coronoid fragments and burring of any associated chondromalacic cartridge and 9 dogs were managed conservatively. All dogs were administered a 6-week course of oral tepoxalin on enrollment. Inverse dynamics gait analysis was performed at initial presentation and at 4, 8, 26, and 52 weeks. The gait variables analyzed were elbow moment (EM), elbow power (EP), total support moment (TSM), and total support moment ratio (TSMR) as a measure of forelimb asymmetry. RESULTS Affected peak EM increased from 0.58 to 0.76 Nm/kg in the AT dogs, and from 0.66 to 0.81 Nm/kg in the CM dogs and there was no significant difference between groups. Affected peak EP increased marginally in the AT dogs, but was unchanged in the CM dogs and there was no significant difference between groups. TSM increased from 1.49 to 1.92 Nm/kg in the AT dogs and from 1.52 to 2.06 Nm/kg in the CM dogs and there was no significant difference between groups. TSMR was statistically different between treatment groups at 1 (P = .003) and 2 months (P = .048) with the AT group more asymmetric and hence more lame. TSMR at 12 months was 0.83 (AT) and 0.86 (CM) implying a failure of return to soundness by either group. CONCLUSIONS AT dogs had increased mechanical asymmetry at 4 and 8 weeks compared to the CM group revealing surgery worsened limb function. There was no significant difference in mechanical symmetry between groups at 26 and 52 weeks.

Comparison of bone mineral density in medial coronoid processes of dogs with and without medial coronoid process fragmentation

OBJECTIVE To quantify bone mineral density (BMD) in the medial coronoid process (MCP) of dogs with and without fragmented medial coronoid processes (FMCPs) by use of dualenergy x-ray absorptiometry. SAMPLE POPULATION 50 osteochondral samples from 31 dogs that underwent subtotal coronoid ostectomy for unilateral or bilateral FMCP and 10 control osteochondral samples of the MCP collected from forelimbs of 5 cadaveric Greyhounds. PROCEDURES Each sample was mounted in proximodistal and mediolateral orientations for BMD determinations via dual-energy x-ray absorptiometry, and area-of-interest data (0.03-cm(2) increments) were obtained. Values of BMD were compared between left and right limb control samples, between control and FMCP samples, and between axial and abaxial regions of the control or FMCP samples. RESULTS The BMD in control and FMCP samples in both proximodistal and mediolateral orientations differed significantly. Mean BMD throughout the MCP was decreased in FMCP samples, compared with control sample findings. In both control and FMCP samples, BMD of the abaxial half of the MCP was 50% higher than that of the axial portion. CONCLUSIONS AND CLINICAL RELEVANCE The similar pattern of BMD in osteochondral samples of the MCP in dogs with and without FMCP indicated that the MCP was eccentrically loaded during weight bearing. Topographic variation in BMD in the MCP, and hence tolerance to compressive loading, suggested that the abaxial portion of the MCP in dogs was more resistant to compressive load than was the axial edge. This difference may predispose the coronoid process to microcrack formation and fragmentation at that juxtaposition.

Can owners and clinicians assess outcome in dogs with fragmented medial coronoid process

OBJECTIVES To investigate the long term reliability of clinician and owner visual analogue score (VAS) for dogs with unilateral forelimb lameness attributable to fragmented medial coronoid process (FMCP) when compared to objective gait analysis. METHODS Nine dogs with unilateral thoracic limb lameness due to FMCP underwent inverse dynamics gait analysis at initial presentation, and at one, two, six and 12 months following diagnosis. Total support moments were calculated and a total support moment ratio (TSMR) derived as an objective assessment of thoracic limb asymmetry. A VAS questionnaire for lameness was completed by the owner of each dog for each visit. Video footage of each dog walking and trotting at each visit was compiled, assigned to random order and subjected to VAS for lameness by a specialist in small animal surgery. Data from owner and clinician VAS lameness questionnaires were compared to the thoracic limb TSMR. RESULTS Statistical analysis demonstrated a significant negative correlation between TSMR and owner VAS at four weeks post treatment but at no other period of evaluation. There was no significant correlation between TSMR and clinician VAS score at any evaluation period. CLINICAL SIGNIFICANCE Assessments by owner and clinicians using VAS appear to be of limited use as a long term outcome measure for dogs with unilateral lameness due to FMCP when compared to objective gait analysis. There is a tendency for owners to underestimate forelimb lameness with increasing time which is not supported by quantitative measures of gait.

Postoperative Complications after Surgical Management of Incomplete Ossification of the Humeral Condyle in Dogs

Objective: To describe incidence and type of postoperative complications in the surgical management of incomplete ossification of the humeral condyle (IOHC) and identify any risk factors associated with development of these complications. Study Design: Case series. Methods: Clinical records of dogs (n=57) that had prophylactic transcondylar screw insertion for treatment of IOHC (79 elbows) at 6 UK referral centers were reviewed. Signalment, presentation, surgical management, postoperative care, and complications were recorded. Postoperative complications were divided into seroma, surgical site infections (SSI) and implant complications. Results: Spaniel breeds and entire males were overrepresented. The overall complication rate was 59.5%. Seroma (n=25) and SSI (24) were the most commonly encountered complications. Implant failure occurred in 2 dogs. Labrador retrievers were at greater risk of developing a postoperative complication than other breeds (P=.03). Increasing bodyweight was a significant risk factor for development of a SSI (P=.03). Placement of the transcondylar screw in lag fashion rather than as a positional screw reduced the incidence of postoperative SSI (P=.007). Conclusions: Surgical management of IOHC is associated with a high rate of postoperative complications. Placement of the transcondylar screw in lag fashion may limit postoperative complications and warrants further consideration.OBJECTIVE To describe incidence and type of postoperative complications in the surgical management of incomplete ossification of the humeral condyle (IOHC) and identify any risk factors associated with development of these complications. STUDY DESIGN Case series. METHODS Clinical records of dogs (n=57) that had prophylactic transcondylar screw insertion for treatment of IOHC (79 elbows) at 6 UK referral centers were reviewed. Signalment, presentation, surgical management, postoperative care, and complications were recorded. Postoperative complications were divided into seroma, surgical site infections (SSI) and implant complications. RESULTS Spaniel breeds and entire males were overrepresented. The overall complication rate was 59.5%. Seroma (n=25) and SSI (24) were the most commonly encountered complications. Implant failure occurred in 2 dogs. Labrador retrievers were at greater risk of developing a postoperative complication than other breeds (P=.03). Increasing bodyweight was a significant risk factor for development of a SSI (P=.03). Placement of the transcondylar screw in lag fashion rather than as a positional screw reduced the incidence of postoperative SSI (P=.007). CONCLUSIONS Surgical management of IOHC is associated with a high rate of postoperative complications. Placement of the transcondylar screw in lag fashion may limit postoperative complications and warrants further consideration.

Canine elbow dysplasia 1. Aetiopathogenesis and diagnosis

CANINE elbow dysplasia is a term encompassing multiple developmental anomalies of the cubital joint, including elbow incongruity, a fragmented medial coronoid process, an ununited anconeal process, osteochondrosis of the humeral condyle and an ununited medial epicondyle. Collectively, these lesions are a common cause of thoracic limb lameness in juvenile medium‐ and large‐breed dogs. However, the precise mechanisms by which these anomalies arise are still unknown. Diagnosis in some cases can be challenging, as can be determining the most appropriate course of treatment. This article reviews current understanding of the aetiopathogenesis of canine elbow dysplasia and outlines the approach to diagnosing the most common developmental anomalies associated with this condition. An article in the next issue will discuss the treatment and prognosis.

Clinical Comparison of the Hybrid Dynamic Compression Plate and the Castless Plate for Pancarpal Arthrodesis in 219 Dogs

OBJECTIVE To describe and compare a large population of dogs that had pancarpal arthrodesis (PCA) using either a hybrid dynamic compression plate (HDCP) or a CastLess Plate (CLP). STUDY DESIGN Multicenter, retrospective, cohort study. ANIMALS Dogs (n = 240; 261 PCA). METHODS Medical records (2000-2012) from 12 UK orthopedic centers were reviewed for dogs that had PCA to document signalment, diagnosis, arthrodesis method, and complication rates. Follow-up data were used to compare outcome (lameness evaluation and radiographic healing) after use of HDCP and CLP plates. RESULTS PCA was performed with HDCP in 125 cases, CLP in 105, and by other techniques in 31. Carpal hyperextension injury was the most common diagnosis in HDCP and CLP groups. Surgical site infection (18.3%) was the most common postoperative complication. There was no difference in intra- (11% HDCP, 21% CLP) or postoperative (34% HDCP, 41% CLP) complication rates. Use of external coaptation did not affect postoperative complication rates or outcome. External coaptation related complications occurred in 32% HDCP and 18% CLP (P = .02). At median follow-up, most dogs were classified as having no or mild lameness (73% HDCP, 83% CLP) and there was radiographic healing in 40% HDCP and 46% CLP (P = .8) cases. CONCLUSIONS CLP and HDCP may both be used successfully to achieve pancarpal arthrodesis. Adjunctive external coaptation does not appear to have a measurable clinical benefit but is associated with morbidity.

The use of transarticular external skeletal fixation in the management of failed tibial tuberosity transposition in five dogs

The management of tibial tuberosity fracture-avulsion after tibial tuberosity transposition can be challenging. Implants must be able to resist the strong distractive force of the quadriceps mechanism, yet implant size is limited by the amount of tuberosity bone stock available. Revision fixation is compromised further by fragmentation of the tubercle. Five stifle joints had temporary transarticular external skeletal fixators applied to manage complications of tibial tuberosity transposition. Fracture reduction was confirmed in four out of five tibial tuberosity fractures. Frames were in place for a mean of 44 days. Frame associated complications occurred in four out of five limbs, the most common being pin tract discharge and associated osteolucency. All frame-associated complications resolved. Long-term follow-up information was available for three of the five animals at 13 to 18 months after frame removal. All three owners reported occasional lameness, but this was attributed to concurrent orthopaedic disease. Transarticular external skeleton fixation protects internal fixation techniques, and good limb function was achieved in most cases. Transarticular external skeleton fixation can be successfully used to augment repair of tibial tuberosity fracture after tibial tuberosity transposition.